Cleaning oily aperture blades - Minolta AF 50 mm F1.4

The following video demonstrates how I clean the aperture blades
of my Minolta AF 50 mm F1.4 lens.
This is a fast and easy way to disassemble only the necessary parts,
remove and clean the aperture blades and assemble the lens again.
With this method I don't get rid of the oil forever, but I can use
the lens for 6-12 months until the next cleaning procedure is necessary.

[@tageandersen2549]

I have had the same problem with this lens and its aperture blades, so it was a great relief finding your video on KZbin. I studied your video a couple of times and then went to work. I found it easy to disassemble the lens and get to the aperture construction and clean the blades and the tube. It was a bit more troublesome to assemble the blades and put the the entire assembly into the right place in the tube, but at last I succeeded, and now I have got a real fine working and faultless lens. Your video has been a great help! THANK YOU!

[@CRVideoTutorials]

Thank you for your comment! Glad that my video was helpful. : )

[@errolrojas3460]

Trying to figure out when he marked with the white marker how come this does not show up when he reassembles. The tutorial is good, just needed to do a couple of close ups.

[@g10118]

@@errolrojas3460 He looked through the back, that's why he took the mounting plate off.

[@faqmoroz]

Thank you for video, construction of minolta 50 1.7 is exactly the same, most challenging part is to reassembly aperture blades and install it

[@CRVideoTutorials]

Yes, that's the tricky part. It takes some time, but with some patience it is possible. : )

[@tonybaker55]

Mine has just started to slow down, so I was thinking about opening it up, but my dexterity does not stretch to this. Great video for those brave ones out there though.

[@MartinAraka]

Thanks ☺️. I had a lens that was stuck wide open and I managed to fix it!!

[@CRVideoTutorials]

That's great! Thanks for your comment!

[@suzesiviter6083]

lol do not attempt unless you have the patience of a saint! All parts relatively easy if you are used to small screws and have a good magnetic screwdriver, the hardest part is inserting the aperture into the lens from the bottom whilst keeping both parts together and aligned. Also, the clip can be a pain to get off, I used a stanley knife to prize off as the blade is thin and strong. Great guide thank you!

[@CRVideoTutorials]

Thanks for your comment!

[@suzesiviter6083]

@@CRVideoTutorials Thank you, got a working lens now, the video gave me the confidence to attempt.

[@CRVideoTutorials]

@@suzesiviter6083 That's very cool - glad the video helped!

[@samsen3965]

Is this the same for 50mm F1.7 af maxxum too or that is different internally?

[@CRVideoTutorials]

I am not sure, if there are any major differences between the two lenses. I guess there are not to many and the principle should not be that much different.

[@samsen3965]

@@CRVideoTutorials 🙏🏻

[@roblevin14]

My front element is so tight that I can't move it. Any tips on how to remove the front element?

[@CRVideoTutorials]

Maybe it will work if you use rubber gloves or something that sticks to the element, so that your fingers don't slip away while trying to unscrew it.

[@roblevin14]

Thank you - I figured out what I was doing wrong - Like trying to unscrew the barrel of the lens which is a solid piece of aluminum instead of the center cap. The next challenge I am having is trying to re-install the aperture blade assembly. Very challenging. It keeps on coming apart. You make it look so simple. Already spent 3-4 hours just on that part of the assembly. FYI I am also wearing gloves because I don't want oil from my skin getting on the blades

[@CRVideoTutorials]

Don't give up - when I cleaned the lens for the first time, I had the same problem. : ) It is a bit tricky, but it works. You can't really damage anything when you are a bit careful, so keep on trying. You can try to place the aperture assembly on something like a piece of plastic tube ore something with a proper diameter and lift it back in the lens.

[@roblevin4754]

Not giving up and actually not frustrated ....yet. I can reassemble the iris assembly and re-install it with ease however it doesn't seem to seat properly because when I flip it over the iris leaves are loose and flops around. Am I am missing some step to seat that assembly? FYI I am using the rubber foot of a 1" cane to re-install the assembly (the 1" end not the 1 3/4" base). It works very well

[@CRVideoTutorials]

Hm, that's strange. When I flip the lens over - which should be done carefully, of course - the iris leaves stay in position. Then, after fixating the iris assembly with the metal ring, everything should stay as it is.

[@NorbertHildebrandt-u8f]

Just don't make that effort. Simply unscrew the bayonet at the back, then unscrew the rear pair of lenses and then carefully immerse the lens in a bowl of cleaning petrol. The Lammela should be flooded. Hold the lamella down and operate several times until the oil has been washed away. Let it dry. Install rear pair of lenses, screw 3 screws and bayonet 4. That's it!!!

[@veiledzorba]

Ok, so I'm not understanding why you need to keep doing this? Where is the oil coming from?

[@CRVideoTutorials]

Some moving parts are greased. Over time, oil leaks out of the fat, which then adheres to the aperture blades.